gdb depends on libpython3.8

[JeremyGrosser]

After switching to the gnat-fsf-13.1.0 toolchain, arm-eabi-gdb stops working on Debian bookworm, because libpython3.8.so.1.0 is unavailable. Python 3.11 is the release included with Debian stable.

synack@polar ~/src/rp2040_hal/tests(master) $ eval $(alr printenv)
synack@polar ~/src/rp2040_hal/tests(master) $ arm-eabi-gdb
arm-eabi-gdb: error while loading shared libraries: libpython3.8.so.1.0: cannot open shared object file: No such file or directory